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Dive into the research topics where Yaw Nyame is active.

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Featured researches published by Yaw Nyame.


Clinical Cancer Research | 2014

Vitamin D deficiency predicts prostate biopsy outcomes

Adam B. Murphy; Yaw Nyame; Iman K. Martin; William J. Catalona; Courtney M.P. Hollowell; Robert B. Nadler; James M. Kozlowski; Kent T. Perry; Andre Kajdacsy-Balla; Rick A. Kittles

Purpose: The association between vitamin D and prostate biopsy outcomes has not been evaluated. We examine serum vitamin D levels with prostate biopsy results in men with an abnormal prostate-specific antigen and/or digital rectal examination. Experimental Design: Serum 25-hydroxyvitamin D (25-OH D) was obtained from 667 men, ages 40 to 79 years, prospectively enrolled from Chicago urology clinics undergoing first prostate biopsy. Logistic regression was used to evaluate the associations between 25-OH D status and incident prostate cancer, Gleason score, and tumor stage. Results: Among European American (EA) men, there was an association of 25-OH D <12 ng/mL with higher Gleason score ≥ 4+4 [OR, 3.66; 95% confidence interval (CI), 1.41–9.50; P = 0.008] and tumor stage [stage ≥ cT2b vs. ≤ cT2a, OR, 2.42 (1.14–5.10); P = 0.008]. In African American (AA) men, we find increased odds of prostate cancer diagnosis on biopsy with 25-OH D < 20 ng/mL [OR, 2.43 (1.20–4.94); P = 0.01]. AA men demonstrated an association between 25-OH D < 12 ng/mL and Gleason ≥ 4+4 [OR, 4.89 (1.59–15.07); P = 0.006]. There was an association with tumor stage ≥ cT2b vs. ≤ cT2a [OR, 4.22 (1.52–11.74); P = 0.003]. Conclusions: In AA men, vitamin D deficiency was associated with increased odds of prostate cancer diagnosis on biopsy. In both EA and AA men, severe deficiency was positively associated with higher Gleason grade and tumor stage. Clin Cancer Res; 20(9); 2289–99. ©2014 AACR.


American Journal of Men's Health | 2012

Predictors of Serum Vitamin D Levels in African American and European American Men in Chicago

Adam B. Murphy; Brian Kelley; Yaw Nyame; Iman K. Martin; Demetria J. Smith; Lauren Castaneda; Gregory J. Zagaja; Courtney M.P. Hollowell; Rick A. Kittles

Vitamin D deficiency is epidemiologically linked to prostate, breast, and colon cancer. When compared with European American (EA) men, African American (AA) men have increased risk of prostate cancer, but few studies evaluate vitamin D status in AA men. The authors evaluate the biological and environmental predictors of vitamin D deficiency in AA and EA men in Chicago, Illinois, a low ultraviolet radiation environment. Blood samples were collected from 492 men, aged between 40 and 79 years, from urology clinics at three hospitals in Chicago, along with demographic and medical information, body mass index, and skin melanin content using a portable narrow-band reflectometer. Vitamin D intake and ultraviolet radiation exposure were assessed using validated questionnaires. The results demonstrated that Black race, cold season of blood draw, elevated body mass index, and lack of vitamin D supplementation increase the risk of vitamin D deficiency. Supplementation is a high-impact, modifiable risk factor. Race and sunlight exposure should be taken into account for recommended daily allowances for vitamin D intake.


The Prostate | 2013

Smoking and Prostate Cancer in a Multi-Ethnic Cohort

Adam B. Murphy; Folasade Akereyeni; Yaw Nyame; Mignonne C. Guy; Iman K. Martin; Courtney M.P. Hollowell; Kelly Walker; Rick A. Kittles; Chiledum Ahaghotu

Prostate cancer (PCa) and smoking‐related morbidity disproportionately burdens African American (AA) men. Smoking is associated with high‐grade PCa and incidence, but few studies have focused on AA men. This study aims to determine the effect of tobacco‐use on odds of PCa and of high‐grade PCa in a population of predominantly AA men.


Journal of Clinical Oncology | 2016

Associations Between Serum Vitamin D and Adverse Pathology in Men Undergoing Radical Prostatectomy

Yaw Nyame; Adam B. Murphy; Diana K. Bowen; Gregory Jordan; Ken Batai; Michael A. Dixon; Courtney M.P. Hollowell; Stephanie J. Kielb; Joshua J. Meeks; Peter H. Gann; Virgilia Macias; Andre Kajdacsy-Balla; William J. Catalona; Rick A. Kittles

PURPOSE Lower serum vitamin D levels have been associated with an increased risk of aggressive prostate cancer. Among men with localized prostate cancer, especially with low- or intermediate-risk disease, vitamin D may serve as an important biomarker of disease aggression. The aim of this study was to assess the relationship between adverse pathology at the time of radical prostatectomy and serum 25-hydroxyvitamin D (25-OH D) levels. METHODS This cross-sectional study was carried out from 2009 to 2014, nested within a large epidemiologic study of 1,760 healthy controls and men undergoing prostate cancer screening. In total, 190 men underwent radical prostatectomy in the cohort. Adverse pathology was defined as the presence of primary Gleason 4 or any Gleason 5 disease, or extraprostatic extension. Descriptive and multivariate analyses were performed to assess the relationship between 25-OH D and adverse pathology at the time of prostatectomy. RESULTS Eighty-seven men (45.8%) in this cohort demonstrated adverse pathology at radical prostatectomy. The median age in the cohort was 64.0 years (interquartile range, 59.0 to 67.0). On univariate analysis, men with adverse pathology at radical prostatectomy demonstrated lower median serum 25-OH D (22.7 v 27.0 ng/mL, P = .007) compared with their counterparts. On multivariate analysis, controlling for age, serum prostate specific antigen, and abnormal digital rectal examination, serum 25-OH D less than 30 ng/mL was associated with increased odds of adverse pathology (odds ratio, 2.64; 95% CI, 1.25 to 5.59; P = .01). CONCLUSION Insufficiency/deficiency of serum 25-OH D is associated with increased odds of adverse pathology in men with localized disease undergoing radical prostatectomy. Serum 25-OH D may serve as a useful biomarker in prostate cancer aggressiveness, which deserves continued study.


The Journal of Urology | 2017

Intermediate-Term Outcomes for Men with Very Low/Low and Intermediate/High Risk Prostate Cancer Managed by Active Surveillance

Yaw Nyame; Nima Almassi; Samuel Haywood; Daniel Greene; Vishnu Ganesan; Charles Dai; Joseph Zabell; Chad Reichard; Hans Arora; Anna Zampini; Alice Crane; Daniel Hettel; Ahmed Elshafei; Khaled Fareed; Robert J. Stein; Ryan K. Berglund; Michael Gong; J. Stephen Jones; Eric A. Klein; Andrew J. Stephenson

Purpose: We compare intermediate term clinical outcomes among men with favorable risk and intermediate/high risk prostate cancer managed by active surveillance. Materials and Methods: A total of 635 men with localized prostate cancer have been on active surveillance since 2002 at a high volume academic hospital in the United States. Median followup is 50.5 months (IQR 31.1–80.3). Time to event analysis was performed for our clinical end points. Results: Of the cohort 117 men (18.4%) had intermediate/high risk disease. Overall 5 and 10‐year all cause survival was 98% and 94%, respectively. Cumulative metastasis‐free survival at 5 and 10 years was 99% and 98%, respectively. To date no cancer specific deaths had been observed. Overall freedom from intervention was 61% and 49% at 5 and 10 years, respectively. Overall cumulative freedom from failure of active surveillance, defined as metastasis or biochemical failure after local therapy with curative intent, was 97% and 91% at 5 and 10 years, respectively. Of the men 21 (9.9%) experienced biochemical failure after deferred treatment and the 5‐year progression‐free probability was 92%. Compared to men with favorable risk disease those with intermediate/high risk cancer experienced no difference in metastases, surveillance failure or curative intervention. However, patients at higher risk were at significantly increased risk for all cause mortality, likely reflecting patient selection factors. These conclusions may be limited by the small number of events and the duration of our study. Conclusions: Patients with localized prostate cancer who are on active surveillance demonstrated a low rate of active surveillance failure, prostate cancer specific mortality and metastases regardless of baseline risk.


The Prostate | 2016

External validation of a PCA-3-based nomogram for predicting prostate cancer and high-grade cancer on initial prostate biopsy

Daniel Greene; Ahmed Elshafei; Yaw Nyame; Onder Kara; Ercan Malkoc; Tianming Gao; J. Stephen Jones

The aim of this study was to externally validate a previously developed PCA3‐based nomogram for the prediction of prostate cancer (PCa) and high‐grade (intermediate and/or high‐grade) prostate cancer (HGPCa) at the time of initial prostate biopsy.


Cancer Epidemiology, Biomarkers & Prevention | 2014

Are HIV-Infected Men Vulnerable to Prostate Cancer Treatment Disparities?

Adam B. Murphy; Ramona Bhatia; Iman K. Martin; David A. Klein; Courtney M.P. Hollowell; Yaw Nyame; Elodi Dielubanza; Chad J. Achenbach; Rick A. Kittles

Background: HIV-infected (HIV+) men face cancer treatment disparities that impact outcome. Prostate cancer treatment and treatment appropriateness in HIV+ men are unknown. Methods: We used electronic chart review to conduct a retrospective cohort study of 43 HIV+ cases with prostate cancer and 86 age- and race-matched HIV-uninfected (HIV−) controls with prostate cancer, ages 40 to 79 years, from 2001 to 2012. We defined treatment appropriateness using National Comprehensive Cancer Network guidelines and the Charlson comorbidity index (CCI) to estimate life expectancy. Results: Median age was 59.5 years at prostate cancer diagnosis. Median CD4+ T-cell count was 459.5 cells/mm3, 95.3% received antiretroviral therapy, and 87.1% were virally suppressed. Radical prostatectomy was the primary treatment for 39.5% of HIV+ and 71.0% of HIV− men (P = 0.004). Only 16.3% of HIV+ versus 57.0% of HIV− men received open radical prostatectomy (P < 0.001). HIV+ men received more radiotherapy (25.6% vs. 16.3%, P = 0.13). HIV was negatively associated with open radical prostatectomy (OR = 0.03, P = 0.007), adjusting for insurance and CCI. No men were undertreated. Fewer HIV+ men received appropriate treatment (89.2% vs. 100%, P = 0.003), due to four overtreated HIV+ men. Excluding AIDS from the CCI still resulted in fewer HIV+ men receiving appropriate treatment (94.6% vs. 100%, P = 0.03). Conclusion: Prostate cancer in HIV+ men is largely appropriately treated. Under- or overtreatment may occur from difficulties in life expectancy estimation. HIV+ men may receive more radiotherapy and fewer radical prostatectomies, specifically open radical prostatectomies. Impact: Research on HIV/AIDS survival indices and etiologies and outcomes of this prostate cancer treatment disparity in HIV+ men are needed. Cancer Epidemiol Biomarkers Prev; 23(10); 2009–18. ©2014 AACR.


The Journal of Urology | 2018

Genomic Scores are Independent of Disease Volume in Men with Favorable Risk Prostate Cancer: Implications for Choosing Men for Active Surveillance

Yaw Nyame; Dominic C. Grimberg; Daniel Greene; Karishma Gupta; Ganesh Kartha; Ryan K. Berglund; Michael Gong; Andrew J. Stephenson; Cristina Magi-Galluzzi; Eric A. Klein

Purpose: We sought to determine whether disease volume at prostate biopsy would correlate with genomic scores among men with favorable risk prostate cancer. Materials and Methods: We identified all men with NCCN® (National Comprehensive Cancer Network®) very low and low risk disease who underwent Oncotype DX® prostate testing at our institution from 2013 to 2016. Disease volume was characterized as the percent of positive cores, the number of cores with greater than 50% involvement, the largest involvement of any single core and prostate specific antigen density. Nonparametric testing was performed to compare the median Genomic Prostate Score™ and the likelihood of favorable pathology findings between quartiles of disease volume. Results: We identified 112 (37.8%) and 184 men (62.2%) at NCCN very low and low risk, respectively. Median scores did not differ significantly between disease volume quartiles (all p >0.05). However, the median likelihood of favorable pathology findings statistically differed between volume quartiles (all <0.05). Seven of the 105 men (6.3%) with very low risk disease were reclassified at low risk and 13 of 181 (7.2%) with low risk disease were reclassified at intermediate risk. Genomic disease reclassification did not depend on biopsy tumor volume. Conclusions: In patients with NCCN very low and low risk prostate cancer genomic scores did not demonstrate meaningfully significant differences by volume based on clinically established cutoff points. Moreover, genomic scores identified and reclassified men with higher risk disease despite generally acceptable surveillance characteristics in this group according to grade and volume. This suggests that in patients at low risk the tumor biological potential measured by genomics rather than by volume should inform decisions on active surveillance candidacy.


Prostate Cancer and Prostatic Diseases | 2017

Does prostate volume correlate with vitamin D deficiency among men undergoing prostate biopsy

Adam B. Murphy; Yaw Nyame; Ken Batai; R Kalu; A Khan; Pooja Gogana; Michael A. Dixon; Virgilia Macias; Andre Kajdacsy-Balla; Courtney M.P. Hollowell; William J. Catalona; Rick A. Kittles

Objectives:Recent studies demonstrate vitamin D is inversely correlated with BPH and prostate cancer (PCa) incidence. We aim to clarify the associations of vitamin D with prostate volume.Methods:This is an observational study investigating the associations of serum PSA, PSA density and prostate volume with serum 25-hydroxyvitamin D (25-OH D) in PCa patients and men with negative biopsies seen in outpatient urology clinics in Chicago, IL, USA. There were 571 men (40–79 years old) with elevated PSA or abnormal digital rectal examination with available prostate volume recorded from initial biopsy. The primary outcomes were the unadjusted associations of serum 25-OH D deficiency with prostate volume. The secondary outcomes were the adjusted associations using linear and logistic regression analysis.Results:On univariate analysis, serum 25-OH D<20 ng ml−1 inversely correlated with prostate volume among all men undergoing transrectal ultrasonography (P=0.02), and this relationship remained significant for men with negative biopsy on stratified analysis. In adjusted models, controlling for age, serum PSA, 5-α reductase inhibitors use, obesity and PCa diagnosis, prostate volume was inversely associated with vitamin D (P<0.05) using serum vitamin D as a continuous and categorical variable. Logistic regression model also demonstrated an inverse association between vitamin D (continuous and categorical) and prostate volume ⩾40 grams.Conclusion:Serum 25-OH D levels are inversely associated with overall prostate volume and enlarged prostate gland (⩾40 grams), especially in men with benign prostatic disease. Given the largely non-toxic effect of supplementation, consideration should be given to assessing vitamin D levels in men with benign prostatic disease in addition, to malignant prostatic disease.


The Journal of Urology | 2016

Clinical Predictors of 30-Day Emergency Department Revisits for Patients with Ureteral Stones

Vishnu Ganesan; Christopher Loftus; Bryan Hinck; Daniel Greene; Yaw Nyame; Sri Sivalingam; Manoj Monga

PURPOSE Patients with ureteral stones frequently present to the emergency department for an initial evaluation with pain and/or nausea. However, a subset of these patients subsequently return to the emergency department for additional visits. We sought to identify clinical predictors of emergency department revisits. MATERIALS AND METHODS We reviewed emergency department visits at our institution with an ICD-9 diagnosis of urolithiasis and an associated computerized tomography scan between 2010 and 2013. Computerized tomography studies were independently reviewed to confirm stone size and location, and degree of hydronephrosis. The primary outcome was a second emergency department visit within 30 days of the initial visit for reasons related to the stone. Patient characteristics and stone parameters at presentation were recorded. Univariable and multivariable analyses were done to identify factors associated with emergency department revisits. RESULTS We reviewed the records of 1,510 patients 18 years old or older who presented to the emergency department with a diagnosis of ureteral stones confirmed by computerized tomography. Of the patients 164 (11%) revisited the emergency department within 30 days. On multivariable analysis the presence of a proximal ureteral stone, age less than 30 years and the need for intravenous narcotics in the emergency department remained independently associated with an emergency department revisit. CONCLUSIONS Younger patients, those with proximal stones and those requiring intravenous narcotics for pain control are more likely to return to the emergency department. Consideration should be given for early followup or intervention for these patients to prevent costly emergency department returns.

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